TB-500
A synthetic peptide based on the active region of thymosin beta-4, studied for tissue repair, cell migration, and regenerative research.
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What is TB-500?
TB-500 is a synthetic peptide based on the active region of thymosin beta-4 (Tβ4), a naturally occurring 43-amino-acid protein encoded by the TMSB4X gene. The compound marketed as TB-500 is generally a shortened synthetic peptide corresponding to amino acids 17-23 of native thymosin beta-4 (the LKKTETQ sequence), often N-acetylated for stability. This fragment was identified through structure-function research as the region responsible for many of the actin-binding and cell migration effects of the full-length protein.
TB-500 is notable in research for its broad applications across regenerative biology. Thymosin beta-4 is one of the most abundant intracellular proteins in mammalian cells, where it serves as the primary actin-sequestering molecule and plays roles in cell migration, angiogenesis, and wound healing. The synthetic fragment retains many of these activities in preclinical models, and the peptide has been investigated across tendon, ligament, muscle, cardiac, and ophthalmic tissue repair contexts.
Mechanism of action
TB-500’s mechanisms of action have been investigated across multiple pathways:
- Actin sequestration: The peptide binds monomeric G-actin in a 1:1 stoichiometry, regulating actin polymerization dynamics critical for cell motility, division, and tissue remodeling.
- Cell migration: Studies have documented enhanced directional migration of endothelial cells, keratinocytes, corneal epithelial cells, and tissue-resident progenitor cells toward sites of injury.
- Angiogenesis: Research has shown promotion of new blood vessel formation through effects on endothelial cell migration, proliferation, and tube formation.
- Anti-inflammatory effects: Preclinical models have demonstrated reductions in pro-inflammatory cytokine expression and modulation of macrophage polarization at injury sites.
- Stem and progenitor cell recruitment: Studies have observed effects on recruitment and migration of progenitor cells from bone marrow and tissue niches, particularly in cardiac and cerebrovascular injury models.
These pathways are characterized primarily in rodent models and in vitro systems.
Research applications
TB-500 has been investigated across several preclinical research domains, with the most active areas including:
- Musculoskeletal injury models: Animal studies have observed accelerated repair in transected tendons, ligament damage models, and muscle injury models, with effects on cell migration to the injury site driving much of the observed regeneration.
- Cardiac repair research: Studies in myocardial infarction models have examined effects on cardiomyocyte survival, recruitment of epicardial progenitor cells, and post-infarction remodeling.
- Wound healing and dermal research: Models of dermal wounds, burns, and pressure ulcers have demonstrated accelerated wound closure, reduced scarring, and improved tissue quality in preclinical contexts.
- Ophthalmic research: Full-length thymosin beta-4 has been examined in clinical research for dry eye disease and neurotrophic keratopathy, with effects on corneal epithelial cell migration and repair.
- Neurological injury research: Models of traumatic brain injury, stroke, and certain neurodegenerative processes have examined the peptide’s neuroprotective and repair-promoting effects.
This compound is intended for laboratory research use only. It has not been approved for human therapeutic use by any regulatory agency.
Storage & reconstitution
In its lyophilized form, TB-500 tolerates ambient temperatures during shipping but should be stored long-term at -20°C, protected from light. Properly stored lyophilized peptide remains stable for 24 months or longer.
Once reconstituted with bacteriostatic water for injection, TB-500 solutions should be stored refrigerated at 2-8°C and used within 28 days. Avoid repeated freeze-thaw cycles, which can degrade peptide structure and reduce activity.
Visual inspection should be performed before each use. The reconstituted solution should be clear and colorless. Reject any solution that appears cloudy, discolored, or contains visible particulate matter.
For step-by-step reconstitution calculations, see our reconstitution calculator.
For laboratory research use only. The compound described on this page is intended exclusively for in vitro research and laboratory experimentation by qualified researchers and is not for human or veterinary use. It is not a drug, food, dietary supplement, or cosmetic, and has not been approved by the FDA, Health Canada, EMA, or any other regulatory authority for the diagnosis, treatment, cure, mitigation, or prevention of any disease or medical condition. The information provided on this page is for educational and reference purposes only and does not constitute medical advice. By accessing this content you confirm that you are a qualified researcher purchasing for legitimate laboratory purposes.